IRD ScramJet Bottom Bracket (BSA w/Hybrid Ceramic Bearings)
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The IRD ScramJet incorporates a hybrid ceramic bearing system. This is a cartridge system that involves a single ceramic ball with the remaining balls being steel. These balls are encased within steel races.
Don’t confuse these with “other” hybrid ceramic bearing systems that use all ceramic balls and steel races. Steel ball bearings have advantages over ceramic other than just cost.
They are stronger than ceramic thus have higher load ratings. Ceramic balls are much harder than steel balls, but this also means they are more brittle, thus they have lower load ratings than steel bearings.
The ScramJet was built with strength and durability as its design goal. The ScramJet combines the strength of steel and the hardness of ceramic to extend bearing life.
When a contaminate enters, the extremely hard ceramic ball will pulverize it rendering it harmless within the bearing system.
Furthermore, if the race has been damaged by sand or any other contaminant the extremely hard ceramic ball will cold work the steel race; continually polishing it with every rotation, actually repairing the it.
Although this might seem too magical to believe, many other industries use this technology to dramatically increase bearing life by several times. They are some times referred to as self healing bearings.
• Precision-machined Aluminum cups
• Adjustable Aluminum Dust Sleeve is expandable to fit shells 68mm to 100mm
• Self-cleaning Hybrid Ceramic Technology
• 5-year warranty on bearings
• BSA (English) threads
• Fits 24mm axle cranks: Shimano Hollowtech II, some Race Face, FSA MegaExo, etc (not GXP)
• Made in Japan